This invention is directed to a flow conditioner utilized to reduce flow meter measurement errors in a tubular conduit in which a fluid flow including liquids, gases and mixtures thereof is contained. Swirl, turbulence or poor flow distribution or a combination thereof often occur in fluids flowing through a tubular pipe especially after two out-of-plane 90° bends and these undesirable conditions make it difficult to obtain reliable flow measurement, i.e., by the placement of a venturi device flow meter in the conduit. This undesirable condition has led to the use of flow conditioners placed downstream of the conduit portion causing maldistribution, etc. and upstream of the measuring device.
An effective commercially available mixer that also serves to condition flow is described in applicant's previous U.S. Pat. No. 5,839,828 issued Nov. 24, 1998 to Robert W. Glanville. The device disclosed in such patent operates in part by creating trailing vortices which contribute to better flow distribution. The teachings of U.S. Pat. No. 5,839,828 are hereby incorporated into the present specification by specific reference thereto.
It would be desirable to reduce/eliminate the above undesirable flow conditions by providing a flow conditioner which is simple, effective and low cost and that provides such results with an extremely low pressure head loss. This and other objects of the present invention are accomplished by a flow conditioning device positioned in said conduit and within a fluid stream having a longitudinal flow direction with said passageway, said device including a first stage and a second stage wherein said second stage is positioned immediately downstream of said first stage, said first stage comprising a plurality of primary vane members forming a set thereof, said vanes spaced generally circumferentially equidistantly within said conduit and radially inwardly extending from said conduit internal wall surface towards the center of said conduit, each of said primary vane members including a generally oblong plate of planar extent with a generally straight base edge attached to said internal conduit wall and further including a leading edge upstanding from a base edge forward portion to a peak from which, in turn, a rearwardly downwardly curved trailing edge extends and terminates proximal the rear portion of said base edge, each of said plates including a generally triangularly-shaped cap attached and conforming to said curved trailing edge thereof with the cap apex aligned with said leading edge peak so as to form cap undersurfaces and cap top surfaces and said second stage comprising a plurality of secondary vanes each having a secondary plate member including a base edge surface disposed against the conduit surface at an offset position vis-à-vis the positions of said primary vanes, said secondary plates radially inwardly extending into the fluid stream and, said secondary plates including a flat wing member extending laterally therefrom.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.